Bernard Fermini1, David S Ramirez1, Sunny Sun1, Asser Bassyouni1, Michelle Hemkens1, Todd Wisialowski1, Stephen Jenkinson2. 1. Global Safety Pharmacology, Pfizer Worldwide Research and Development, La Jolla, CA 92121, United States; Global Safety Pharmacology, Pfizer Worldwide Research and Development, Groton, CT 06340, United States. 2. Global Safety Pharmacology, Pfizer Worldwide Research and Development, La Jolla, CA 92121, United States; Global Safety Pharmacology, Pfizer Worldwide Research and Development, Groton, CT 06340, United States. Electronic address: stephen.jenkinson@pfizer.com.
Abstract
INTRODUCTION: Although therapeutically beneficial in the treatment of certain diseases, L-type calcium channel antagonism can result in unwanted off-target pharmacology leading to adverse drug reactions and to the termination of the development of otherwise promising compounds. In the present study three marketed calcium channel inhibitors, nifedipine, verapamil and diltiazem were profiled in a series of in vitro and ex-vivo assays in an effort to determine the ability of these assays to discriminate, between dihydropyridine versus non-dihydropyridine-like compounds, and how well they can predict the cardiovascular effects observed in a conscious telemetered rat model. METHODS: Standard calcium channel antagonists were profiled in radioligand binding, patch clamp and calcium flux assays. In addition, cardiovascular endpoints related to calcium channel activity were also examined in ex vivo tissue bath preparations, including relaxation of pre-constricted rat aorta and the guinea pig Langendorff isolated heart model. The data generated were correlated with in vivo blood pressure and heart rate data from conscious telemetered rats. RESULTS: Our results show that the binding, FLIPR and aorta assays allow differentiation of the compounds in two distinct classes of L-type calcium channel antagonists, and are good predictors of in vivo outcomes. DISCUSSION: These results suggest that in vitro and ex vivo profiling remains a valuable tool in predicting potential in vivo cardiovascular safety issues, and can aid in the selection of novel development compounds that show inherent inhibitory activity against L-type calcium channels.
INTRODUCTION: Although therapeutically beneficial in the treatment of certain diseases, L-type calcium channel antagonism can result in unwanted off-target pharmacology leading to adverse drug reactions and to the termination of the development of otherwise promising compounds. In the present study three marketed calcium channel inhibitors, nifedipine, verapamil and diltiazem were profiled in a series of in vitro and ex-vivo assays in an effort to determine the ability of these assays to discriminate, between dihydropyridine versus non-dihydropyridine-like compounds, and how well they can predict the cardiovascular effects observed in a conscious telemetered rat model. METHODS: Standard calcium channel antagonists were profiled in radioligand binding, patch clamp and calcium flux assays. In addition, cardiovascular endpoints related to calcium channel activity were also examined in ex vivo tissue bath preparations, including relaxation of pre-constricted rat aorta and the guinea pig Langendorff isolated heart model. The data generated were correlated with in vivo blood pressure and heart rate data from conscious telemetered rats. RESULTS: Our results show that the binding, FLIPR and aorta assays allow differentiation of the compounds in two distinct classes of L-type calcium channel antagonists, and are good predictors of in vivo outcomes. DISCUSSION: These results suggest that in vitro and ex vivo profiling remains a valuable tool in predicting potential in vivo cardiovascular safety issues, and can aid in the selection of novel development compounds that show inherent inhibitory activity against L-type calcium channels.
Authors: Jana Pourová; Lenka Applová; Kateřina Macáková; Marie Vopršalová; Thomas Migkos; Roger Bentanachs; David Biedermann; Lucie Petrásková; Václav Tvrdý; Marcel Hrubša; Jana Karlíčková; Vladimír Křen; Kateřina Valentová; Přemysl Mladěnka Journal: Nutrients Date: 2019-09-24 Impact factor: 5.717